DIGITAL IMAGE DATA FORMATS

DIGITAL IMAGE DATA FORMATS

The image analyst can order digital remote sensor data in a variety of formats.

The most common formats are :

- Band Interleaved by Pixel (BIP),

- Band Interleaved  by Line (BIL), and

- Band Sequential (BSQ).

To appreciate the data formats, consider a hypothetical remote sensing dataset containing

just nine pixels obtained over the interface between land and water. The Image consists

of three bands (band 1=green;band 2=red;band 3=near-infrared).

The brightness value (BVi,j,k) row, column, and band notation is provided (figure 1a).

Band Interleaved by Pixel (BIP) Format

The BIP format places the brightness values in n bands associated with each pixel in the dataset in sequential order [e.g., for a dataset containing three bands the format for the first pixel in the matrix (1,1) is 1,1,1; 1,1,2; 1,1,3]. The brightness values for pixel (1,2) are then placed in the dataset (e.g., 1,2,1; 1,2,2; and 1,2,3), and so on. An end-of-file (EOF) marker is placed at the end of the dataset (figure 1b).

Band Interleaved by Line (BIL) Format

The BIL format creates a file that places the brightness values in n bands assocciated with each line in the dataset in sequential order. For example, if are three bands in the dataset, all of the pixels in line 1, band 2, and the then line 1, band 3. An EOF marker is placed at the end of the dataset (figure 1c).

Band Sequential (BSQ) Formats
The BSQ format places all of the individual pixel values in each band in a separate and unique file. Each band has its own beginning header record and EOF marker (figure 1d).